Which is the best?

[Ravin1337]

Which GSdx is the best?

I currently have mine set to AVX, is that the best one for my GPU?

[Ice Queen Zero]

It's related to your CPU instruction sets.

SSE2 < SSSE3 < SSE41 < AVX

Their difference in performance were minor. I'll just say pick the highest available (seeing your CPU, it's AVX).

[Squall Leonhart]

AVX only provides an improvement when using Software graphics

[Ravin1337]

AVX only provides an improvement when using Software graphics

So AVX essentially provides the same level of HW graphics as SSE41 but has slightly better SW graphics.

[Squall Leonhart]

it performs better(more fps) though the difference is relatively small